/*
 * code found at: http://www.uni-paderborn.de/info/solaris_porting_faq
 */
/*
 * Copyright (c) 1994 Powerdog Industries.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer
 *    in the documentation and/or other materials provided with the
 *    distribution.
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgement:
 *      This product includes software developed by Powerdog Industries.
 * 4. The name of Powerdog Industries may not be used to endorse or
 *    promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY POWERDOG INDUSTRIES ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE POWERDOG INDUSTRIES BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* A few changes by Steve Dekorte:
 * - renamed function and moved En_US into function
 */
#include "Base.h"
#include "PortableStrptime.h"

/*#ifdef IO_NEEDS_STRPTIME*/

#include <time.h>
#include <ctype.h>
#include <locale.h>
#include <string.h>

#define asizeof(a) (sizeof(a) / sizeof((a)[0]))

/*#ifndef sun*/
struct dtconv {
    char *abbrev_month_names[12];
    char *month_names[12];
    char *abbrev_weekday_names[7];
    char *weekday_names[7];
    char *time_format;
    char *sdate_format;
    char *dtime_format;
    char *am_string;
    char *pm_string;
    char *ldate_format;
};
/*#endif*/

#ifdef SUNOS4
extern int strncasecmp();
#endif

#if defined(_MSC_VER) && !defined(__SYMBIAN32__)
#define strcasecmp _stricmp
#define strncasecmp _strnicmp
#endif

int readndigits(char **const buf, const size_t count) {
    int result = 0;
    size_t i;

    for (i = 0; i < count; i++, (*buf)++) {
        const char digit = **buf;
        if (digit == 0 || !isdigit(digit)) {
            break;
        }
        result *= 10;
        result += digit - '0';
    }

    return result;
}

// TODO rename function when I understand what this function does.
void somethingToDoWithSpaces(const char *const buf, char **const ptr) {
    if (*buf != 0 && isspace((int)*buf)) {
        while (**ptr != 0 && !isspace((int)**ptr)) {
            (*ptr)++;
        }
    }
}

char *io_strptime(char *buf, char *fmt, struct tm *tm) {
    struct dtconv En_US = {{"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul",
                            "Aug", "Sep", "Oct", "Nov", "Dec"},
                           {"January", "February", "March", "April", "May",
                            "June", "July", "August", "September", "October",
                            "November", "December"},
                           {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"},
                           {"Sunday", "Monday", "Tuesday", "Wednesday",
                            "Thursday", "Friday", "Saturday"},
                           "%H:%M:%S",
                           "%m/%d/%y",
                           "%a %b %e %T %Z %Y",
                           "AM",
                           "PM",
                           "%A, %B, %e, %Y"};

    char c, *ptr;
    long i, len;

    len = 0;
    ptr = fmt;
    while (*ptr != 0) {
        if (*buf == 0)
            break;

        c = *ptr++;

        if (c != '%') {
            if (isspace((int)c))
                while (*buf != 0 && isspace((int)*buf))
                    buf++;
            else if (c != *buf++)
                return NULL;
            continue;
        }

        c = *ptr++;
        switch (c) {
        case 0:
            return NULL;

        case '%':
            if (*buf++ != '%')
                return NULL;
            break;

        case 'C':
            buf = io_strptime(buf, En_US.ldate_format, tm);
            if (buf == 0)
                return NULL;
            break;

        case 'c':
            buf = io_strptime(buf, "%x %X", tm);
            if (buf == 0)
                return NULL;
            break;

        case 'D':
            buf = io_strptime(buf, "%m/%d/%y", tm);
            if (buf == 0)
                return NULL;
            break;

        case 'R':
            buf = io_strptime(buf, "%H:%M", tm);
            if (buf == 0)
                return NULL;
            break;

        case 'r':
            buf = io_strptime(buf, "%I:%M:%S %p", tm);
            if (buf == 0)
                return NULL;
            break;

        case 'T':
            buf = io_strptime(buf, "%H:%M:%S", tm);
            if (buf == 0)
                return NULL;
            break;

        case 'X':
            buf = io_strptime(buf, En_US.time_format, tm);
            if (buf == 0)
                return NULL;
            break;

        case 'x':
            buf = io_strptime(buf, En_US.sdate_format, tm);
            if (buf == 0)
                return NULL;
            break;

        case 'j':
            if (*buf == 0 || isspace((int)*buf))
                break;

            i = readndigits(&buf, 3);
            if (i < 0 || i > 366)
                return NULL;

            tm->tm_yday = (int)i;
            break;

        case 'M':
            if (*buf == 0 || isspace((int)*buf))
                break;

            i = readndigits(&buf, 2);
            if (i < 0 || i > 59)
                return NULL;

            tm->tm_min = (int)i;

            somethingToDoWithSpaces(buf, &ptr);
            break;

        case 'S':
            if (*buf == 0 || isspace((int)*buf))
                break;

            i = readndigits(&buf, 2);
            if (i < 0 || i > 60) // Earlier 61 was also allowed.
                return NULL;

            tm->tm_sec = (int)i;

            somethingToDoWithSpaces(buf, &ptr);
            break;

        case 'H':
        case 'k':
            if (!isdigit((int)*buf))
                return NULL;

            i = readndigits(&buf, 2);
            if (i < 0 || i > 23)
                return NULL;

            tm->tm_hour = (int)i;

            somethingToDoWithSpaces(buf, &ptr);
            break;

        case 'I':
        case 'l':
            if (!isdigit((int)*buf))
                return NULL;

            i = readndigits(&buf, 2);
            if (i < 1 || i > 12)
                return NULL;

            tm->tm_hour = (int)i;

            somethingToDoWithSpaces(buf, &ptr);
            break;

        case 'd':
        case 'e':
            if (!isdigit((int)*buf))
                return NULL;

            i = readndigits(&buf, 2);
            if (i < 1 || i > 31)
                return NULL;

            tm->tm_mday = (int)i;

            somethingToDoWithSpaces(buf, &ptr);
            break;

        case 'm':
            if (!isdigit((int)*buf))
                return NULL;

            i = readndigits(&buf, 2);
            if (i < 1 || i > 12)
                return NULL;

            tm->tm_mon = (int)(i - 1);

            somethingToDoWithSpaces(buf, &ptr);
            break;

        case 'Y':
            if (*buf == 0 || isspace((int)*buf))
                break;

            if (!isdigit((int)*buf))
                return NULL;

            i = readndigits(&buf, 4);
            if (i < 0 || i > 9999)
                return NULL;

            tm->tm_year = (int)(i - 1900);

            somethingToDoWithSpaces(buf, &ptr);
            break;

        case 'y':
            if (*buf == 0 || isspace((int)*buf))
                break;

            if (!isdigit((int)*buf))
                return NULL;

            i = readndigits(&buf, 2);
            if (i < 0 || i > 99)
                return NULL;

            tm->tm_year = (int)i;

            somethingToDoWithSpaces(buf, &ptr);
            break;

        case 'P':
        case 'p':
            len = strlen(En_US.am_string);
            if (strncasecmp(buf, En_US.am_string, len) == 0) {
                if (tm->tm_hour > 12)
                    return NULL;
                if (tm->tm_hour == 12)
                    tm->tm_hour = 0;
                buf += len;
                break;
            }

            len = strlen(En_US.pm_string);
            if (strncasecmp(buf, En_US.pm_string, len) == 0) {
                if (tm->tm_hour > 12)
                    return NULL;
                if (tm->tm_hour != 12)
                    tm->tm_hour += 12;
                buf += len;
                break;
            }

            return NULL;

        case 'A':
        case 'a':
            for (i = 0; i < (int)asizeof(En_US.weekday_names); i++) {
                len = strlen(En_US.weekday_names[i]);
                if (strncasecmp(buf, En_US.weekday_names[i], len) == 0)
                    break;

                len = strlen(En_US.abbrev_weekday_names[i]);
                if (strncasecmp(buf, En_US.abbrev_weekday_names[i], len) == 0)
                    break;
            }
            if (i == asizeof(En_US.weekday_names))
                return NULL;

            tm->tm_wday = (int)i;
            buf += len;
            break;

        case 'B':
        case 'b':
        case 'h':
            for (i = 0; i < (int)asizeof(En_US.month_names); i++) {
                len = strlen(En_US.month_names[i]);
                if (strncasecmp(buf, En_US.month_names[i], len) == 0)
                    break;

                len = strlen(En_US.abbrev_month_names[i]);
                if (strncasecmp(buf, En_US.abbrev_month_names[i], len) == 0)
                    break;
            }
            if (i == asizeof(En_US.month_names))
                return NULL;

            tm->tm_mon = (int)i;
            buf += len;
            break;
        }
    }

    return buf;
}

/*#endif*/
